1. Field of the Invention
The present invention relates to machines for the continuous casting of metal and, in particular, to systems for handling starter bars which are usually incorporated into such machines.
2. Description of the Prior Art
As is, for example, disclosed in U.S. Pat. No. 3,344,844, molten metal may be continuously cast by pouring it into a flow through type casting mold so as to form an elongate continuous strand of metal. In order to start this strand the mold is initially closed at its lower end with a starter bar and molten metal is allowed to solidify and become fastened to the starter bar. The starter bar is then withdrawn from the mold so that a strand of solidifying metal is formed from the mold along a generally arcuate, downwardly extending path which is defined by a plurality of rollers which may be supported on an apron structure. At the base of this structure, the strand enters a set of straightener pinch rollers through which it passes and emerges as a straightened horizontal casting. Before the strand is straightened, however, the starting bar must be first disconnected and stored, often on a curved starting bar receiving structure that is positioned adjacent the discharge end of the straightener apparatus and above straightened casting.
Various means have been suggested for moving the starting bar, first through its initial downward path, then through the straightener apparatus, and then onto the starting bar receiving structure. In certain designs such movement of the starting bar is accomplished by one or more drive rolls in the straightener apparatus. Starter bar handling mechanisms built according to these designs, however, may often have certain disadvantages. The starter bar, for example, may eventually become deformed by such mechanisms due to the continuous pressure exerted on it by the rollers. Undue wear on the rollers may also result. Further, in such designs the rollers are often powered by two or more direct current electric motors which may have to be mounted in close proximity to the hot strand and which usually must be synchronized with one another to prevent damage to the strand. Other designs employ a single elevated pivoting arm to move the starter bar along its downward arcuate path, through the straightener apparatus and then onto its receiving structure. While such designs appear to alleviate some of the above mentioned problems, some difficulties may still attend their use. It is, therefore, the object of the present invention to provide a mechanism which effectively handles the starter bar without causing undue deformation or damage to the strand and which may be powered by a single drive means positioned remotely from the hot strand.